Sediment yield prediction and prioritization of sub-watersheds in the Upper Subarnarekha basin (India) using SWAT

• Published in: Arabian journal of geosciences 2021-05, Vol.14 (9), Article 809
• Main Authors: Panda, Chinmaya, Das, Dwarika Mohan, Raul, Sanjay Kumar, Sahoo, Bharat Chandra
• Format: Article
• Language: English
• Subjects: Algorithms; Calibration; Catchment area; Earth and Environmental Science; Earth science; Earth Sciences; Hydrologic models; Land use; Original Paper; Sediment; Sediment yield; Soil conservation; Soil erosion; Soil properties; Soil texture; Soil water; Texture; Uncertainty; Water conservation; Watersheds; Yield forecasting
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-021-07170-8

The present study deals with the estimation of soil loss from the Upper Subarnarekha catchment in Odisha (India) using Soil and Water Assessment Tool (SWAT). Sequential uncertainty fitting (SUFI-2) algorithm of the SWAT calibration uncertainty programs (SWAT-CUP) was used for model simulation. The model was calibrated with the observed data for the period from 1996 to 2008 with first 3 years (1996–1998) as warm-up period. Further, validation of the model was done using 5-year data from 2009 to 2013. Reliable evaluation of the model performance during calibration has been substantiated by the coefficient of determination ( R 2 ), Nash–Sutcliffe efficiency (NSE), and percentage bias (PBIAS) as 0.81, 0.81, and −0.15, respectively, and the respective values for the validated model were found to be 0.79, 0.78, and −0.19. The values of P-factor and R-factor were found to be 0.80 and 0.75 and 0.66 and 0.74, respectively, for model calibration and validation. Average annual soil loss from the catchment was 4.84 Mg ha −1 . The watershed indexed as SW18 resulted in highest soil loss in the range of 10–15 Mg ha −1 year −1 . Further, prioritization was done at the level of sub-watersheds using the data of simulated sediment yield, soil texture, land use, and slope for identifying vulnerable sub-watersheds that need immediate attention. The study inferred that sub-watersheds having index numbers SW17, SW18, and SW19 are highly vulnerable, and hence top priority should be given to these sub-watersheds for reduction in soil erosion through the implementation of suitable soil and water conservation measures.